# MAT 540 MAT540 Week 4 Quiz

MAT 540 Week 4 Quiz

- Find the standardized variable
*z*if*x*has Mean 12 and standard deviation 4. - Find the area under the standard normal curve to the right of
*z*= 1.55. Round to four decimal places. - Find the area under the standard normal curve to the left of
*z*= 2.63 - Find the area under the standard normal curve over the interval
*z*= âˆ’0.53 to*z*= 0.53. Compute probabilities using the standard normal table in Appendix B (Table 3). Round the answer to four decimal places. - Scores on a certain nationwide college entrance examination follow a normal distribution with a mean of 550 and a standard deviation of 100. Find the probability that a student will score over 690.Â Round your answer to four decimal places.
- Scores on a certain nationwide college entrance examination follow a normal distribution with a mean of 500 and a standard deviation of 100. Find the probability that a student will score between 350 and 620.Â Round your answer to four decimal places.
- A population has mean 53 and standard deviation 12.Â Calculate the mean of
*x*bar for a random sample of size 10. - A population has mean 53 and standard deviation 12.Â Calculate the standard deviation of
*x*bar for a random sample of size 12. - Suppose the weights of packages of lettuce coming off a packaging line have a normal distribution with mean 8.4 ounces and standard deviation 0.4 ounce. If every package is labeled 9.2 ounces, what proportion of the packages weigh less than the labeled amount?
- Suppose the weights of the contents of cans of mixed nuts have a normal distribution with mean 32.8 ounces and standard deviation 0.4 ounce.

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If two packages are randomly selected, what is the probability that the average weight is less than 32 ounces?

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Round to one decimal place.